[drastic.]

Just serviced a '11 boxxer rc today, and the manual calls for 290ml on the damper side stanchion.

I pumped the damper rod to circulate the oil, then measured the oil height from the top of the fork leg.

manual calls for 290ml of fluid, and a height of 105mm from the top. with 290ml of oil poured in, the height of the oil is actually around 85mm from the top of the leg. 20mm height difference is pretty significant. The fork was completely disassembled and drained/cleaned, so there wasn't any excess oil from prior use.

Which is the correct(er) method? I'm assuming the taller height in the leg is going to have a more pronounced effect on damping than volume, and thus should have a larger priority.

thoughts?

 

[HAB]

You're going to be able to measure volume more accurately. Go with that.


In any case, the Boxxer is an open bath so the exact oil volume isn't as critical as it is in a cartridge damper where any air in it is bad.

 

[DirtyMike]

On open bath systems I have always gone with oil height. Too much oil height, too little oil height can seriously change the characteristics of the fork.

 

[HAB]

On open bath systems I have always gone with oil height. Too much oil height, too little oil height can seriously change the characteristics of the fork.

If you're way off, sure. But a little doesn't matter so much.

 

[samnation]

Whichever works for your settings. I would assume that you are fairly safe to play with the 20mm of height to change up your damping a bit.

That said I ALWAYS go by volume. Except for as mentioned cartridges where it needs to be full.

 

[Lelandjt]

Changing the oil height won't affect the damping so long as you have the minimum amount necessary to submerge the damper. Rather it affects the progressiveness of the spring in the second half of travel because you're changing the air volume. I recommend starting with the minimum amount and adding oil if you need bottoming resistance.

The specs you are going by are probably a typo with both the "recommended" volume and height falling within the accepted range. If I were you I'd call Rockshox to ask what the min and max oil volumes are.